Alabama Landscapes

Energy

Coal

Coal is a sedimentary rock composed of semi-decayed and compressed plant material. The plants grew in permanently wet lowland areas, such as temperate and tropical river deltas, and high latitude bogs and swamps. As the plant material died it was buried beneath mud and sand and slowly began to decay under oxygen-deficient conditions. Burial caused the plant material to transform into coal.  The type, or rank of the coal, depending on the burial (Table CL1):

 Table CL1.  Ranks of Coal.

Economic deposits of Pennsylvanian-aged bituminous coal occur in the northern part of the state (Figure CL1).  The deposits are divided geographically into four regions or "fields:" Warrior Basin and Plateau, which occur in the Cumberland Plateau  physiographic section, and Cahaba and Coosa, which occur in the Valley and Ridge section. 

Figure CL1.  Coal Fields of Alabama (Cartographic Research Laboratory, Dept. of Geography, University of Alabama)

Although the Coosa and Cahaba fields were mined extensively in the 19^th century, today most coal is produced from the Warrior field.  The lignite fields of the Coastal Plain are not presently economic to mine.

Coal production has varied dramatically in the last century of so (Figure CL2).  Increases in production in the early 20th century paralleled the growth of the steel making industry, but several major downturns occurred about 1920, the early 1930s and from 1950 to mid 1960s.   Highest production occurred about 1990 with about 28 mst ( million short tons).  Since then production has decreased to 22 mst  in 2004.  In 2004 49 mines were active, with about 77% located in Walker, Jefferson and Tuscaloosa counties (Figure CL1).  Production has changed from mainly surface mines to mainly deep mines: 84% percent of production came from subsurface (deep) mines in 2004. 

Figure CL2.  Coal production in Alabama 1880-2003. (USGS http://pubs.usgs.gov/of/1997/of97-447/Appalachian.htm)

In the 21st century coal primarily is used to generate electricity (Figure CL3).

Figure CL3.  Sources of energy used for electricity generation 2001. (EIA http://www.eia.doe.gov/emeu/states/main_al.html)

Estimates suggest that Alabama has about 2,800 mst of extractable coal in the ground.   Click here to see what that means for the future.

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